In-place stump grinding has proven an excellent alternative to uprooting for tree stump removal. A variety of stump grinding machines are known. One highly successful device is described in the commonly owned U.S. Pat. No. 5,115,845 to Hooser, which is incorporated herein by reference to the extent pertinent.
Because of the harsh service conditions, grinding stump removers wear greatly on their cutting devices. In order to avoid frequent tool replacements, cutting devices for grinding stump removers must be highly durable. One exceptionally durable cutting device is disclosed in U.S. Pat. No. 5,365,986 to Hooser, which is also commonly owned and incorporated herein by reference. The cutting device disclosed in that patent has a rigid hub with plural arms distributed about the hub and cutting tools mounted to each of the arms.
Being safe, durable, and relatively fast working, the device discussed above compares well to the available alternatives. Despite its success, a major concern with all such parts for service equipment is replacement cost. Until now, the more durable cutting devices for grinding stump removers have been integrated units that, when worn out, must be fully replaced. This constraint has undesirably contributed to the overall cost of operating stump grinders.
Efforts at creating modular cutting devices that could be partially rather than fully replaced has been complicated in that stump grinding relies on fast rotation. Even a slight imbalance in the cutting device tends to generate rotational instability, making the grinding machine difficult or dangerous to use.
Accordingly, there continues to be a need for a durable, yet cost-effective cutting device for grinding machines.